Electrical instrument.



No. 635,910. Patented Oct. 3I, |899. W. 8.' BOULT.

ELECTRICAL INSTRUMENT.

(Application filed May 2, 1899.) "(No Model.)

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YVILFRID SIVANWICK BOULT, OF LONDON, ENGLAND.

ELECTRICAL NSTRUM ENT.

SPECIFICATION forming part of Letters Patent No. 635,910, dated October 31, 1899.

Original application filed December 30,189?,` Serial No. 664,585. Divided and this application fi1ed May 2, 1899. Sor'ial No. 715,357. (No model.)

To (tZZ w/oom it may concern:

Beit known that I, W ILFRID SwANwIOK BOULT, a subject of the Queen of England, residing at London, England, have invented certain new and useful Improvements in or Relating to Electrical Instruments, (for which I have made application for Letters Patent in Great Britain under No. 20,257, dated December 10, 1897,) of which the following is a specification.

This application is a division of my prior application, Scrial No. 664,585, filed December 30, 1897.

This invention relates to electrical instruments, and has special reference to indicator and relay movements, where a tongue or needle is moved to and from a magnetized core or between two such cores.

In polarized relays as ordinarily construct` ed the tongue, which is polarized by, say, a permanent nagnet, vibrates between the two poles of an electromagnet, its movement being caused by the reversal of the current in the coils ofthe electromagnet. In such instruments it is necessary to work with a very slight angular movement of the tongue in order to avoid reversing the polarity of the tongue by the action of that pole of the electromagnet to which the tongue is adjacent when the current is passed around the coils. Even with a small angular movenent of the tongue its polarity is sometimes reversed when a current of greater strength than that for which theinstrument is adjusted is passed around the electromagnet. In instruments according to this invention there is practically no danger of reversing the polarity of the tongue; and, moreover, it is possible to work with an extremely large angular niotion, ninety degrees having been obtained in practice, and therefore the movement is suitable for many purposes-for instance, for use in indicators, switches, the., for which purposes the ordinary relay movement is quite unsuitable.

In carrying out this invention the magnetic flux due to the current passing around a core is caused to divide, part of it passing through another core, against which the tongue is for the moment lying, and the other portion passing through the tongue itself, and consequently magnctizing it, in a sense, Similar to that of the adjacent core. Mutual repulsion between this core and the tongue then takes place, and the latter flies away from the core and is brought back in any convenient way-- for example, by the action of a spring or, as will be hereinafter more fully described, by causing the repelling-core to be energized in its turn. If the tongue is polarized by a permanent magnet, the construction of the instrunent nay be such that its magnetism is strengthened by the flux from the temporarily-active core, thus rendering the repelling action of the other core nore certain and tending to avoid reversal of the magnetism of the tongue. The risk of such reversal is further minimized by the fact that the mag netic iiux from the energized or temporarily active core is divided between the tongue and the other core, and consequently the polarity of the latter is considerably weaker than that of the energized core.

Instruments according to this invention are preferably constrncted with a base of magnetic material iron or steel, for exam ple-and all the cores and tongues employed in the particular instruments are mounted upon or magnetically conneoted to` this base.

In the accompanying drawings, Figures l, 2, and 3 are plans showing diagrammatically various forms of instruments, all according to this invention. Fig. sis a plan showinga portion of amodified form of instrument, and Fig. 5 is a side elevation of the same.

Like letters indicate like parts throughout the drawings.

A, Fig. 1, is a base-plate of magnetic material-say iron-having mounted upon it two soft-iron cores B and B' and a pillar C, which is in this instance a permanent magnet. Upon the upper end of the permanent magnet O is pivotally mounted a tongue D, of soft iron or steel, which is polarized by the permanent magnet. E E' are windings upon the cores B B respectively, and are ener gized separately-that is to say, when a current passes through the coil E the core B' is temporarily the active core, the core B being magnetized not by its own winding E, but by part of the fiux due to the current in the ooil E'.

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The action of the device is as follows: Suppesing that the tongue D is magnetized by the magnet C, so that its end lying against the end of the core B is a north pole, a current is sent through the coil E in such a direction that the top end of the core B' is made a south pole. The magnetic fiux due to the current around the core B' passes into the base A and divides, part of it passing up through the core B, making its upperend a north pole, while part goes through the permancnt magnet O and tongue D, strengthening their polarity. Strong repulsion occurs between the top of the core B and the tongue D, and the latter tlies over to the core B', which is simultaneouslyattracting it very strongly. If the current is now sent through the coil E, so that its upper end becomes a south pole, reactions sinilar to those above take place, and the tongue returns to its first position.

Fig. 2 shows a similar instrument having, however, a double-ended tongue D', each end of which is acted upon by one of the cores B B'.

Fig. 3 illustrates a form of instrument in which, as is sometimes the case, it is desired to have the tongue D normally in a central position between the two cores B B'. This is accomplished by nounting the tongue D upon a pillar C', of soft iron, and placing upon the same base A a permanent magnet 0 so that when no current is flowing through either of the coils E E the tongue D is held in a position central between the two cores B 17. The action in this case is ver Similar to that hereinbetore described with reference to Fig. l, the permanent magnet 0 merely acting as a magnetic control for the tongue D when neither of the coils E E' is energized. It is preferred to pass the current through the coils B and B', so that the polarityof the permanent magnet 0 is strengthened-that is to say, if the latter is a north pole at its upper end whenever the coil B or the coil B is energized the current passes in such a direction as to make the top end of the core a south pole.

A convenient method of grouping the cores and tongues together is shown in Figs. et and 5.

Here there are three cores B B 13 upon a common magnetic base A. Twopillars 0 0 preferably permanent magnets with similar poles at their upper ends, are also mounted upon the base A and carry pivoted tongues D D respectively. Each of the cores B B' B is furnished with a separate winding E, E', or E?, and if by the action of the cores B or 13 either or both of the tongues D D are deflected away from the Central core B' they are brought back by the latter when it is energized. The core B is shown provided with a double-ended pele-piece B and the tongues D and D are provided with contacts D' which when the tongues are detlected make contact with insulated pins B in the cores B and 13 l lt is to be understood that in instruments according to this invention the tongue may,

except it be magnetically controlled, as in Fig. 3, be of soft iron or other magnetic inaterial polarized or unpolarized by a pernanent magnet, or it may itself be of hard steel permanently magnetized. In each case it is, however, essential that the tongue shall be mounted upon or magnetically connected with a magnetic base upon which the cores are mounted. Further, it will be evident that it is not necessary always to surround both the cores with a winding-tor instanee, in the arrangement shown in Fig. 1 the winding E around the core B might be omitted, and thus the core B' would always be the active one. In such a case the return of the tongue l) to the core l would be brought about by the action of a spring, by hand, or otherwise.

I claim- 1. In a relay or other electrical instrument, the combination with a pair of magneticallyconnected cores and means for temporarily cnergizing one of said cores whereby the other core is given an opposite polarity, of a deilectable tongue magnetically connected with said cores and controlled in its movement by the cores; substantially as described. 2. In a relay or other clectrical instrument, the combination with a pair of magneticallyconnected cores and means for temporarily energizing either one of said cores, whereby the other core is given au oppositc polarity, of a polarized deflectable tongue controlled by' said cores; substantially as described.

3. In a relay or other electrical instrument the combination with a core surrounded bya coil through which a current is passed of a second core and a detlectable tongue the magnetic tlux from the first core passing partly through the second core and partly through the tongue.

In a relay or other electrical instrunent the combination of two cores each having a separate winding and a detlectable tongue mounted upon or magnetically connected to a magnetic base common to the two cores.

5. In a relay or other electrical instrument the combination of a plurality of cores having separate windings, and deilectable tongues placed between the cores, the cores and tongues being mounted upon or magnetically connected to a common magnetic basc substantially as set forth.

6. In a relay or other eleetrieal instrument, the combination with a pai'r of magneticallyconnected cores, and means for temporarily energizing either of said cores, whereby the other core is given an opposite polarity, of a polarized de tlectable tongue magnetically connected with said cores and controlled by the cores; substantially as described.

In testimony whereof I have hereunto set my hand in the presence of the two subscribin g witnesses.

KVILFRID SWANWICK BOULT.

Witnesses:

ALFRED J. BOULT, HARRY B. BRIDGE.

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